FR2623679A1 - Device for inspecting a batch of parcels intended to be dismantled and palletising robot containing same - Google Patents

Abstract

Device for inspecting a batch of parcels with a view to its dismantling, including preferably a lighting system 11, an image capturing system and an image processing system 12, characterised in that this image capturing system includes a linear camera arranged along a first direction in practice horizontal carried by a carriage which can move relative to a framework along a direction in practice horizontal above the batch of parcels and distinct from the first direction, the speed of displacement of the carriage relative to the framework being taken into account by a computer which, on the basis of the successive viewing lines of the linear camera, builds a virtual image of the batch of parcels.

Description

 The invention relates to inspection'd a batch of packages. for example placed on. or in a support (pallet, box-pallet, container - -.) in order to determine the positions of the packages in the space then for example to order the dismantling, possibly by a robot of palletization equipped with a hand grasping.

 Such an inspection of the lot of parcels is necessary before any seizure to distinguish those parcels which are directly accessible from those which are less easily accessible, or that they belong to the upper layer of the lot of parcels being surrounded by all dimensions by d other parcels. especially that they belong to a lower layer.

 A good control of the operations of dismantling of this batch of parcels supposes indeed the acquisition of the coordinates of the various parcels to make it possible to program consequently the successive movements of the hand of grip.

For reasons of productivity, recent developments in the field of depalletization (of one or more batches of homogeneous or heterogeneous packages simultaneously aimed for automatic capture of these coordinates without direct human intervention
The French patent 81 17158 published under the number 2.512.357 has thus proposed to recognize packages belonging to the upper layer of a stack of parcels by tracking. using a fixed inspection system overlooking the parcel lot. parcels whose upper face (if all packages have identical upper faces) or whose target (if all -collars have identical targets) has a maximum apparent size.

 In this patent. the inspection system considered is a video camera. This solution. complemented by appropriate image analysis means. gives satisfaction but imposes an important court and complex computer processing.

 The invention aims at constituting the image of a lot of packages in a simpler way. less expensive and faster.

 There are various systems of pattern recognition and image analysis. which are currently used to control dimensions of parts under constant lighting and constant distance.

 However, given the size of the volume to inspect for the dismantling of one or more lots of packages such as a pallet (in practice a volume of 1.2 mx 1.2 mx 2 m) and the desired accuracy. none of these recognition systems can satisfactorily address the problem posed above as a whole.

 To overcome this deficiency, the invention proposes a device for inspecting a package of parcels with a view to dismantling it. having an image capture system and an image processing system, comprising a linear camera disposed in a first direction carried by a movable carriage with respect to a bed parallel to a face of the package lot in a second distinct direction from the first direction. the speed of displacement of the carriage with respect to the frame being taken into account by a calculator which. at. The successive lines of observation of the linear camera constitute a virtual image of the batch of packages. An illumination system is advantageously provided to avoid variations in ambient lighting: this, however, becomes useless. If the ambient lighting is uniform .

According to preferred features of the invention:
said carriage is movable above the batch of parcels and the first and second directions are horizontal; alternatively, a batch of parcels can be inspected by one side or both on the top and on one side in certain particular cases (for example stacks of elongated packages arranged side by side and inspected frontally)
the first and second horizontal directions are perpendicular
the carriage carrying the linear camera is secured to a movable element of a fixed or mobile palletising robot. this element being horizontally movable in translation
- This carriage is linked in translation to the gripping hand that includes this robot
- lbrsque the camera is carried by a robot.

it can hear both cantilever arm type and robot-gantry type. or any other type of robot with Cartesian coordinates.

the invention also proposes a fixed or mobile palletizing robot comprising a vertical column movable horizontally in translation on a fixed or movable base. a horizontal arm perpendicular to this column and vertically movable in translation along this column. and a gripping hand movable in translation along this arm. comprising a linear camera arranged in a first horizontal direction on a carriage movable towards the base in a second horizontal direction distinct from the first direction. å this camera being associated a computer adapted from the successive observation lines identified by the linear camera and the speed of movement of the carriage relative to the base; to constitute a virtual image of a lot of parcels disposed under the camera, and an image processing system connected to the computer Advantageously this device further comprises a lighting system preferably fixed with respect to the carriage
According to preferred embodiments of the invention
the second horizontal direction is perpendicular to the arm.

the first horizontal direction, perpendicular to the second horizontal direction, is parallel to the arm,
the carriage carrying the linear camera is driven in horizontal translation by the column carrying the arm,
- The carriage is linked to the gripping hand.

Objects, features and advantages of the invention will become apparent from the description which follows, given by way of nonlimiting illustrative example with reference to the appended drawing in which:
- Figure 1 is a perspective view of a palletization fixing robot # palletizing equipped with an inspection system according to the invention. and
- Figure 2 is a perspective view of a mobile palletizing / depalletizing robot for the preparation of orders, also equipped with this inspection system.

 This robot, designated as a whole by the reference 1. comprises a fixed base 2 provided with a rail 2A on which moves horizontally along an axis X-X.

 a column 3 which itself carries a horizontal arm 4 perpendicular to the rail 2A and movable vertel lelong this column along an axis Z-Z '. On this arm is mounted a carriage 5. movable horizontally along a third axis "-Y ', vis-a-vis which a gripping hand 6 qlis comes projecting downwards.

 This hand is advantageously adapted to turn towards the carriage 5 about a vertical axis Z-Z.

 This arm is intended to move over a lot 7 of packages 8. identical (or all provided with identical labels forming targets in contrast to the parv package). It may even be parcels without labels, which may have different dimensions, as long as these possible dimensions are all previously known.

 These parcels 8 are here stacked in superposed layers on a pallet 9.

According to the invention. this robot carries a linear camera 10. preferably oriented parallel to the axis
YY 'of the arm 4 and adapted to move transversely to itself, parallel to the axis XX'. a computer connected to this camera and receiving a signal representative of the movement of the camera 10 relative to the base 2 and a treatment system'd images and, preferably. a lighting system 11 ensuring uniform lighting of the packages.

 In the example considered, the computer and the image processing system are combined in a computer t2 provided with a control keyboard 13 and a display screen 14 adapted to display the image of the batch of parcels. or, after treatment, an image of the upper layer of packages. This computer is advantageously further connected to the entire robot to control the operation depalletization.

Preferably, the camera 10 and the lighting system are carried by the carriage S which carries the hand grasping 6. According to a variant not shown, the lighting system is carried by the arm
The device 1- of Figure 2 differs from that of Figure% 'in that its base 2' is itself mobile, on rails here parallel to the axis
X-X ', to allow the taking or laying of parcels in various batches 7A. 78 and TC.

The linear camera 10 is of the CCD sensor type with a number of pixels greater than a thousand,
The camera is placed to acquire a series of lines consisting of points. whose lighting varies This set of lines constitutes the virtual image of the layer.

 It should be noted that the large number of pixels of this type of camera allows a great discretization of what constitutes the stored image of the layer and that it is not necessary to put a target on the packages.

 Once reconstituted by the computer from n rows successively taken by the camera ID. and stored, what can be called the virtual image of the layer is processed by several algorithms of any appropriate type so as to output the coordinates of the various packages in space.

 The coordinates are stored as files directly exploitable by a robot for de-palletization applications (of one or more batches), order preparation or any other need.

 It will be appreciated that the invention makes it possible to automatically acquire the location of parcels in the space for depalletizing applications or automatic order preparation or unbundling of parcels.

The advantage of the invention is to add, on the robot essential to the handling of packages, a camera and its lighting and processing systems and use this robot to move the camera along the most favorable axis and to acquire the virtual image of each layer. This does not imply any additional cost for moving the linear camera implemented according to the invention
The invention does not require a variable focus on the camera lens.

 During the scanning phase. which can be done in time mask the camera acquires n lines, each consisting of more or less illuminated pixels.

 These data are stored in the calculator as well as the reference elements necessary for the defined processing, namely the dimensions of the packages or parts. higher level of parcels.

 An algorithm makes it possible to extract the positions of the pixels where the transitions between different lighting zones take place.

 Another algorithm makes it possible to reconstruct by comparing the transitions with the reference element, the positions and orientations of the packages or parts.

 Additional software must take into account lighting irregularities, lens distortion and irregular camera movement.

 In practice, the camera is brought, for each inspection phase, to a predetermined height.

 Once this information is processed, it is extracted a file directly transformable robot movements, or viewable on a computer screen.

It goes without saying that the above description has been proposed by way of non-limiting example and that many variants can be proposed by those skilled in the art without departing from the scope of the invention. So for example. the camera and its lighting system can be adapted to the robot independently of the arm, for example on the base 2. The lighting system can also only title carried by the base while the camera is carried by the carriage S. L The entire inspection system 1 11 12 can even be carried by a frame that is entirely independent of the robot. In the configuration of FIG. 2 the movement of the linear camera above the packages of packages can be obtained by a movement of the mobile base 2 on its rails
By way of example, a simplified flow diagram of the operation of the system represented can be summarized as follows
- storage of information and processing parameters
- detection of the need to recognize a layer
- acquisition of reference elements
- acquisition of the virtual image of the batch of parcels with movement of the robot
- transmission and storage of data
- computer processing and elaboration of an image of the upper layer
- creation of a coordinate file associated with this layer
- choice: file storage, visualization on screen, or control of the robot for depalletization of the layer.

Claims (7)

 1. Device for inspecting a parcel of parcels with a view in particular to dismantling it, comprising an image capture system and an image processing system (12), characterized in that the image capture system comprises a linear camera (10) arranged in a first direction carried by a movable carriage (5), parallel to a face of the parcel lot, with respect to a frame in a direction distinct from the first direction, the traveling speed of the carriage with respect to the frame being taken into account by a calculator (12) which, from the lines of successive observations of the linear camera constitutes a virtual image of the parcel lot.  2. Inspection device according to claim 1. characterized in that said carriage (5) is movable above the parcel lot and the first and second directions are horizontal.  3. Device according to claim 2. characterized in that the first and second horizontal directions are perpendicular  4 Device according to any one of claims 1 to 3. characterized in that the carriage (5) carrying the linear camera (10) is integral with an element (5) of a palletizing robot # of palletization (1, I '>, which is horizontally movable in translation  5.Dispositif according to claim 1 characterized in that this carriage (5) is connected in translation to the gripping hand (6) that includes this robot (1)  6. Device according to any one of claims 1 to 5 characterized in that it comprises a lighting system (11).  7 depalletizing robot comprising a vertical column (3) movable horizontally in translation on a base (2, 2 '> fixed or mobile, a horizontal arm (4) perpendicular to this column and vertically movable in translation along this column, and a gripping hand (fi) movable in translation along the stud characterized in that it comprises a linear camera (10) arranged in a first horizontal direction on a carriage (S) movable towards the base in a second direction horizontally distinct from the first direction, to this camera being associated a calculator (12) adapted from the successive observation lines identified by the linear camera (10) and the speed of movement of the carriage relative to the base, to constitute a virtual image of a lot (7) of packages placed under the camera, as well as an image processing system (12).  8. de depalletization robot according to claim 7 characterized in that the second horizontal direction is perpendicular to the arm (4)  9 depalletization robot according to claim 8 characterized in that the first horizontal direction perpendicular to the second horizontal direction, is parallel to the arm 14).  10. depalletization robot according to claim 8 or claim 9 characterized in that the carriage (5) carrying the linear camera (10) is driven in horizontal translation by the arm (4).  1 1. depaalettisation robot according to claim 10. characterized in that the carriage (5) is connected to the gripping hand (6).  12. depalletization robot according to any one of claims 7 to 11. characterized in that it comprises a lighting system (11).  13. depalletization robot according to claim 12. characterized in that the lighting system is fixed with respect to the carriage.